“What is it like being 92?” I asked him when I visited him at his house on the outskirts of Boliqueime, a village in the Algarve, in September for what turned out to be a moving last interview.

“It’s like being 91,” he said, with a grin.

His wife Cilla – the actress Priscilla Morgan, to whom he has been happily married for 53 years, is 78, and their doting golden retriever Daisy, 10.

Daisy is totally deaf and Clive partially so.

He is also virtually blind, which means he has had to abandon his second most important vocation – painting and drawing.

The Dunns had a studio built and Clive talks wistfully of the pleasurable hours spent there, working at his portraits, landscapes and seascapes.

His youngest daughter, Jessica, inherited this talent and became a professional artist. Her paintings are intermingled with his on the studio’s walls.

I was entranced by Clive and Cilla.

Over dinner in an excellent fish restaurant, they talked appreciatively of the late veteran actress Edith Evans, who provided the wedding cake when they married in Stratford-on-Avon in 1959, and of the young Albert Finney, who presented the newlyweds with a cardboard box filled with fruit and vegetables.

Their nuptials were celebrated in a country hotel where they tuned into the latest episode of The Archers.

Then it was back to work for Cilla, who performed in All’s Well That Ends Well the next evening.

Clive was 48 when he accepted, after some hesitation because his close friend John Le Mesurier was hesitating too, the role of L Cpl Jones, the bumbling old butcher in the sitcom Dad’s Army.

And action: Clive with the Dad's Army cast (Photo: Getty)

On hearing that John had agreed to play absent-minded Sgt Wilson, Clive told his agent to say ‘yes’.

It was, perhaps, the wisest decision of his career, for in only a matter of months Jones, Wilson and Captain Mainwaring became household names.

The reason for Dad’s Army’s popularity is simple. The characters created by Jimmy Perry and David Croft are recognisable human beings rather than vehicles for one-liners written with comedians in mind.

Clive is saddened that he was not invited to speak at the memorial service in March for David Croft.

He observed he was probably rejected as a result of a speech he had once made praising Dad’s Army for the innocence of its comedy with no swear words and no smutty innuendoes.

He ended with the rhetorical question: ‘Isn’t that f***ing marvellous?’

Clive speaks fondly of the cast. He retains special affection for James Beck, the original Pte Joe Walker, who died suddenly during the filming of the sixth series aged 44.

Then there was John Laurie, grizzled, grumpy Pte Frazer.

“He had a very dim view of actors and often said so in words that can’t be repeated.”

But the man Clive loved most was Le Mesurier.

When staying with Clive and Cilla in Portugal, the easily bored Le Mesurier announced he could not think of anything worse than sunbathing by the pool.

He wanted to see and listen to eccentric individuals and, in the company of the Dunns’ daughters, went to cafes or bars in search of them.

Le Mesurier also disliked the honours system and hated actors accepting them.

“Dear boy, how could you?” he remarked when Clive received an OBE.

Clive Dunn in Dads Army (Photo: Rex)

Clive first played an old man aged 19, in JM Barrie’s play Mary Rose for a weekly repertory company in Abergavenny.

His attempts to enlist in the army, navy and air force were dismissed by a succession of stubborn recruiting officers.

On the verge of despair, he applied for a job with the Auxiliary Ambulance Service and was told to start work the next day on a salary of £3 a week.

He became adept at first aid, a skill he would employ to life-saving effect when he finally saw conflict as a private in the 4th Hussars, whose polo-playing and duck-shooting officers filled him with a disgust he still talked about. (Clive voted Labour all his life).

His wartime experiences are recounted in his 1986 autobiography, entitled Permission To Speak.

He was a prisoner-of-war for more than four years.

Wartime life, in Greece, Macedonia, Egypt, Yugoslavia and Austria, where he was imprisoned, was grim, with near-starvation and death everyday realities.

No wonder he enjoyed the sublime silliness of L Cpl Jones.

After being demobilised in 1946 he began to be noticed as an unusually versatile comic actor.

In the 60s he was in the sitcom Bootsie And Snudge, alongside Bill Fraser and Alfie Bass.

He played an old man, of course, as he was later to do in the children’s series Grandad.

Clive and Cilla have lived in Boliqueime for 30 years. Their granddaughters, Alice and Lydia, named after Clive’s beloved aunts, are constant visitors.

I watched a repeat of Dad’s Army on their television. Clive confessed he could not see much of what was going on.

At one point I turned to look at him and noticed he was mouthing the lines he had spoken 40 years earlier. It was a touching, unforgettable, moment.